Elastic scattering of electrons from singly ionized argon

Journal Article · Fri Mar 01 04:00:00 EST 1996 · Physical Review A

DOI:https://doi.org/10.1103/PhysRevA.53.1915· OSTI ID:283410

Griffin, D C ^[1]; Pindzola, M S ^[2]

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1. Department of Physics, Rollins College, Winter Park, Florida 32789 (United States)
2. Department of Physics, Auburn University, Auburn, Alabama 36849 (United States)

Recently, Greenwood {ital et} {ital al}. [Phys. Rev. Lett. {bold 75}, 1062 (1995)] reported measurements of large-angle elastic scattering of electrons from singly ionized argon at an energy of 3.3 eV. They compared their results for the differential cross section with cross sections determined using phase shifts obtained from two different scattering potentials and found large discrepancies between theory and experiment at large angles. They state that these differences may be due to the effects of polarization of the target, which are not included in their calculations, as well as inaccurate representations of electron exchange in the local scattering potentials that are employed to determine the phase shifts. In order to test these proposed explanations of the discrepancies, we have carried out calculations of elastic scattering from Ar{sup +} using the {ital R}-matrix method. We compare both a single-state calculation, which does not include polarization, and a 17-state calculation, in which the effects of dipole polarizability are included through the use of polarization pseudostates within the close-coupling expansion, to each other and with the measurements. We find some differences between the two calculations at intermediate scattering angles, but very close agreement at angles above 100{degree}. Although the calculated cross sections agree with experiment between 120{degree} and 135{degree}, large discrepancies persist at angles above 135{degree}. We conclude that the differences between the measurements and theory cannot be explained on the basis of an inaccurate representation of electron exchange or polarization of the target. {copyright} {ital 1996 The American Physical Society.}

• DOE Contract Number: FG05-93ER54218; FG05-86ER53217
• OSTI ID: 283410
• Journal Information: Physical Review A, Journal Name: Physical Review A Journal Issue: 3 Vol. 53; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ARGON IONS
CROSS SECTIONS
ELASTIC SCATTERING
ELECTRON EXCHANGE
ELECTRON-ION COLLISIONS
EV RANGE 01-10
POLARIZATION